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Archives in Cancer Research
ISSN 2254-6081
One Year Exposure to Nocturnal
7 Hz, Amplitude-Modulated
Magnetic Fields Suppresses
Clinical Expression of DMBAInduced Tumors in Female Rats
2015
Vol. 3 No. 1:2
Michael A. Persinger1,2
Linda S. St-Pierre1
1 Behavioural Neuroscience, Laurentian
University, Sudbury, OntarioP3E 2C6,
Canada
2 Biomolecular Sciences, Programs, Laurentian University, Sudbury, OntarioP3E
2C6, Canada
Corresponding author: Michael A. Persinger
Abstract
Female rats that had received only four oral administrations of Dimethylbenz(a)
anthracene (DMBA) were exposed for one year every night for about 6 min
every hour between midnight and 08 hr to various intensities of 7 Hz, amplitudemodulated magnetic fields generated through Helmholtz coils. The rats exposed to
intensities between 400 and 500 nT did not develop any overt tumors even though
they received DMBA. On the other hand rats exposed to the intensities between 30
and 60 nT developed a variety of different, qualitatively unusual tumors that were
located within pancreatic, salivatory, and nasal tissues. Their histological features
are presented. These results should be considered preliminary but suggest that
protracted exposures to particularly patterned and intensity magnetic fields during
the nocturnal cycle may suppress the chemical reactions that contribute to the
nuclear changes in the cell or the intercellular cohesive networks that ultimately
trigger these massive proliferations of tissue.

mpersinger@laurentian.ca
Behavioural Neuroscience, Laurentian
University, Sudbury, OntarioP3E 2C6,
Canada
Tel: +01-705-675-4824
Fax: +01-705-671-3841
Keywords: DMBA; Nocturnal magnetic field exposure; 7 Hz amplitude-modulation;
Pancreatic tumors; Salivatory tumors; Histology
Introduction
The potential interaction between ambient, biofrequency
electromagnetic fields generated by the technologies of western
civilization and the biological process that produce malignancy has
been supported by a large number of correlation studies and cellculture research [1]. These investigations have focused primarily
upon the influence of 50 Hz or 60 Hz magnetic fields generated by
power lines or indirectly from various configurations of wiring [2].
Critical field strengths for increasing the risk of developing some
form of cancer relative to a reference group varies with the age
of the population and usually involves exposure for several years
to intensities greater than about 1 μT (10 mG). There has been
substantial variability in the odd ratios for exposed populations as
well as effect sizes of the multitude of signaling pathways that are
affected within cell cultures. The potential for interaction between
pharmacological compounds and whole body exposure to power
frequency electromagnetic fields was reviewed by Whissell and
© Copyright iMedPub
Persinger [3]. They suggested that the most challenging problem
in the 21st century will be predicting the synergisms between
drugs or chemicals consumed inadvertently or purposely by
people and the increasingly “bioeffective” electromagnetic
matrix produced by industrial and habitat-related power
frequencies superimposed upon communication technologies.
The latter become relevant when “beat frequencies” within
the 1 Hz to kHz range emerge from the GHz and MHz carriers.
The inspiration for considering such synergism between an
applied, body-permeating electromagnetic stimulus and internal
chemical reactions was derived from the powerful effects
reported by Thomas et al., [4] when they exposed rats to specific
intensities of microwave radiation and a commonly consumed
benzodiazepine. Only when the two stimuli were combined
was the effect conspicuous. Few experiments [5] have been
designed to discern if particular combinations of intensities and
frequencies of applied magnetic fields might modify the untoward
consequences of oncogenic compounds. If the electromagnetic
fields were simulating the types of interactions that occur
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ISSN 2254-6081
between ligands and receptors, very specific parameters would
be required to converge with the required energies and temporal
patterns for the dynamics between boundaries of reactions. For
example in other studies [6,7] we found that female Lewis rats
inoculated with a preparation of spinal cord emulsion did not
develop experimentally allergic encephalomyelitis as severely if
they were exposed continuously to an amplitude-modulated 7
Hz, 50 nT magnetic field for about 6 minutes per hour eight times
during the later scotophase. Neither exposures to the same 7 Hz
amplitude modulated pattern but with a peak of 500 nT or 40 Hz,
50 nT or 40 Hz, 500 nT configurations impeded the development.
The symptoms in rats exposed to these conditions did not differ
from non-treated controls.
In the present experiment we combined the treatments
with dimethylbenz(a)anthracene (DMBA), a drug known to
produce malignancies [8,9], and exposure for one year to the
same, intermittently presented (once per hour, 8 times during
the night phase), 7 Hz, amplitude-modulated magnetic field. We
had selected this frequency based upon the historical literature
concerning the importance of the Schumann resonance [10],
an intrinsic standing wave generated between the earth and
ionosphere and to which all living systems have been exposed
since abiogenesis [11]. We have assumed, in a manner similar to
the unfolding patterns of ontogenesis from a single cell, that the
conditions that occurred when amino acid formation and likely
polypeptide production first occurred may have set the direction
for all subsequent phylogenetic development. Consequently
electromagnetic conditions similar to those inferred to have
been present during abiogenesis may still be relatively potent
modifiers of basic cell dynamics. Here we report the potentially
oncostatic effects of this procedure.
Our hypothesis was that a very narrow range of weak intensity,
appropriately temporally patterned magnetic fields applied
intermittently during the nocturnal period should suppress
chemically-induced tumorogenesis. Approximately 6 minutes
of exposure once per hour were calculated to be sufficient for
influencing cells but without the counterproductive effects of
habituation that sometimes results from continuous exposure.
We selected nocturnal exposures because they would be more
relevant to potential applications to human patients when
protracted exposures would be less restrictive (the patients would
be sleeping) and because of our measurements of the intrinsic
oncostatic effects of physiological levels of melatonin when the
circulating values compensate following brief suppressions during
nocturnal magnetic field exposures. The object of our study was
to discern if nocturnal exposures to these weak but specifically
patterned magnetic fields could elicit qualitatively conspicuous
and robust suppression of malignancies.
Experimental Procedures
A total of 14, Wistar albino female rats, approximately 90 days
of age at the beginning of the experiment were housed 3 to 4 rats
per plastic cage. The housing arrangements are shown in Figure
1. This is the same equipment employed for previous studies
involving treatment of experimental allergic encephalomyelitis
[6] and for inducing nocturnal seizures in rats whose limbic
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2015
Vol. 3 No. 1:2
Figure 1 Coils employed to generate the amplitude-modulated 7
Hz magnetic fields.
Figure 2 Shape of the 7 Hz Hz amplitude-modulated
magnetic field to which the rats were exposed for
5 min and 50 s once per hour 8 times per night for
one year.
epilepsy was induced by lithium and pilocarine [12]. By gavage,
each rat received 1 cc of 2 mg of 7,11,Dimethylbenzl(a)anthracene
(DMBA), a classical tumor-inducing agent, suspended in sesamie
oil once per week for 4 weeks.
Immediately after the first injection the rats were exposed to
one of four different average intensities of magnetic fields: 500
nT (upper left), 400 nT (upper right), 60 nT (lower left) and 30 nT
(lower right) in Figure 1. The fields were generated through two
Helmholtz coils whose characteristics have been reported [12].
Peripheral fields from these coils penetrated into the adjacent
lower two plastic cages. We had established these “indirect”
fields were effective and that the changes were not due to simply
the position in previous experiments [6]. In other words if the
field strengths in the coils were reduced by a factor of 10 to 50 nT,
such that the intensities in the peripheral cages were less than 5
nT, there were no significant effects in the lower cages but only in
the cages with 50 nT intensities.
This experimental arrangement was similar to the procedure
we employed to reduce the severity of experimental allergic
encephalomyelitis or EAE [7]. For one year, every night, a 7 Hz
fundamental square wave created by a function generator was
amplitude-modulated by a Commodore Computer 8 times
per night (scotophase) between midnight and 0706 hr. The
programmed photophase for the room was 12:12 with the
dark onset occurring around 8 P.M. local time. A diagram of the
escalating and deescalating amplitude modulated pattern is
shown in Figure 2. The field pattern was activated for 5 min and
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Archives in Cancer Research
ISSN 2254-6081
2015
Vol. 3 No. 1:2
Necropsies were performed and appropriate pictures were
taken. Sample tissue from the malignant growths were fixed in
ethanol-formalin-acetic acid, processed, sectioned at 6 μ with a
microtome, and stained with toluidine Blue O. The sections were
examined by light microscopy between 40× and 1000×.
Results
Figure 3 Salivatory tumor after about one year subsequent to
the DMBA consumption.
Figure 4 Histopathology of salivatory tumor from Figure 6. (1000×,
oil) Toluidine Blue O.
Figure 5
Pancreatic tumor about one year subsequent to
DMBA consumption.
The results were conspicuous. None of the 7 rats that had
been administered the DMBA over four weeks and exposed to
the 400 to 500 nT, nocturnal, intermittent amplitude-modulated
7 Hz fields developed any discernable tissue anomalies within the
limits of visual inspection during necropsy. However 5 of the 7
rats that had been exposed to the same pattern of magnetic fields
but with intensities between 30 to 60 nT developed conspicuous
tumors peripherally. We had recorded and measured more than
300 rats of approximately 3,000 rats over a 25 year period that
lived to clinical endpoints (two to three years of age). The vast
majority of those tumors were mammary adenocarcinomas
(verified by histology) or fibroadenomas. Two of the rats exposed
to the 30 to 60 nT fields displayed this form. However there were
additional types of tumors obtained with the DMBA treatments
that we have not observed in our rat populations. The first type is
shown for one rat in Figure 3. It was verified as a salivatory tumor
(Figure 4).
The second type of tumor primarily involved the pancreas as
shown in Figure 5. Despite the abdominal distention, this animal
consumed food normally, acquired adipose, and exhibited no
discernable indictors of distress. Even when given the option
to consume Tylenol in solution or tap water in a two bottle
choice paradigm, a procedure which has been shown to reflect
nociception of the animal [13] and allows a rat to “titrate” its
own “level of analgesia” the rat only consumed water. However
the criteria for termination had been met because the rat was no
longer eating and had become lethargic. The right picture reveals
the mass responsible for the abdominal distention.
A closer inspection of the nodular mass within the viscera is
Figure 6 Organ depiction of tumor shown in Figure 5. The
proliferation of anomalous tissue can be seen as
the light yellowish-grey tissue wrapped around the
abdominal mass.
50 s once per hour 8 times per night every night for one year.
Food (Purina rat chow) and water were available ad libitum. The
quarter-inch corn cob that served as bedding for the rats was
removed and replaced once every two to three days before the
onset of the scotophase.
Towards the end of the one year period, as various tumors
became apparent for some exposure intensities, care was taken
to ensure minimum distress for the rats. Approximately one year
after the initial gavaging and the exposure to various intensity
magnetic fields the rats were killed by barbiturate overdose.
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Figure 7 Histopathology at various levels of magnification
(oil=1000×) within pancreatic malignant tissue
shown in Figure 6.
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material is administered. Most studies have pursued the proclivity
for the enhancement of mammary tissues. In our experiments
the material was delivered through the oral-digestive system.
Consequently the occurrence of aberrant growths that slowly
occurred over several months within the salivatory glands, nasal
region (considering the likelihood that some rats may have
aspired some of the substance through the Eustachian tube
during gavaging) and the pancreas might be expected.
Figure 8 Gross display of nasal tumour that developed
over one year in a rat that received the DBMA
treatment.
Figure 9 Histopathology of nasal tumor noted in Figure
10 (100×).
Figure 10 Histopathology of nasal tumor (400×).
Hyaline cartilage is noted on left; mast
cells (deep purple) infiltrating the
connective tissue associated with the
proliferation and external expansion of
the tumor are evident on the right.
shown in Figure 6 before (left) and after (right) removal from the
animal. The absence of food components within the intestines
is evident. Figure 7 shows the histology. Figure 8 through Figure
10 demonstrate the gross characteristics and histology of the
malignant growth within the nasal region of the rat.
Discussion
We have been investigating the effects of various teratogens
and carcinogenic compounds for several decades. DMBA was
selected because of its reliable induction of aberrant or malignant
cells depending upon where within the body boundaries the
4
We had anticipated that the exposure to the same pattern and
intensity of magnetic fields that attenuated experimental allergic
encephalomyelitis would have been most beneficial. However for
this particular treatment the 400 to 500 nT intensities of the 7
Hz amplitude modulated magnetic field were most effective. We
have not observed such efficacy in any of our previous treatments
for delaying or eliminating the growth of tumors. However
in most of our studies the exposures have been much shorter,
such as two or three weeks. Although the sample size might be
considered too small from some perspectives, the qualitatively
conspicuous tumors that occurred in one group (the low intensity
field) compared to the display of no tumors in the group that was
exposed at the same time but to higher intensity fields suggests
this is a powerful effect. We cannot exclude the possibility that
the marked group difference was a combination effect. Whereas
the 400 to 500 nT suppressed malignant cell growth the lower
intensities also increased this growth, thus enhancing the size of
the effect.
Our approach has been that the solution for successful
treatment of oncogenic processes requires the understanding of
the biophysical mechanisms [14] at the level of quantum biology.
Persinger [15] has shown quantitatively that a molarity-based
Jacobson equation for relativistic resonance would be consistent
with the effect upon a molecule with the mass of melatonin.
The critical intensity would be about 10 to 100 nT. Nocturnal
melatonin has been considered an oncostatic compound and
its disruption could have occurred every night because of the
multiple approximately 6 min, 7 Hz magnetic field exposures. It
may be relevant that the 36 mHz and 71 mHz intrinsic periodicities
for the shift in 7 Hz amplitudes (Figure 2) are also congruent
with the resonance solution for calcium within the 15-20 nT
range [15]. If these mechanisms operate in a manner similar to
“narrow band” phenomena, then immediately adjacent bands
(“intensities”) might display enhanced refractory (protective)
properties. Such a relationship would significantly challenge the
classic linear approach to dosimetry for risk of malignant growth
from carcinogenic stimuli.
The major limitation of this experiment was that prolonged
time and investment were required to discern the oncostatic
effects from the appropriate intensity of the magnetic field.
However cancer often develops slowly, over decades, in the
human being. Consequently preventive treatments for those
prone to malignant cell growth might someday require life-long
administration of the appropriately patterned and personalized
magnetic field. If this procedure is effective for human conditions
then the procedure could be applied without any invasiveness
while the person sleeps. It would be analogous to preventing the
opportunity for malaria to develop by sleeping in beds surrounded
by mosquito nets to minimize its initiation by the critical vector.
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ISSN 2254-6081
2015
Vol. 3 No. 1:2
Acknowledgements
Thanks to Dr. Carly Buckner, Julie Charette, and Dr. Mathieu
Dupont for their technical contributions. Special thanks to
Professor Chris Blomme for his advice and vigilance for care of
the animals.
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References
1. Wilson BW, Stevens RG, Andersen LE (1990) Extremely low frequency
electromagnetic fields: the question of cancer. Battelle Press: Wash
pp. 383.
2. Savitz DA, Wachtel H, Barnes FA, John EM, Tvrdik JG (1988) Casecontrol study of childhood cancer and exposure to 60-Hz magnetic
fields. Am J Epidemiol 128: 21-38.
3. Whissell PM, Persinger MA (2007) Emerging synergisms between
drugs and physiologically-patterned weak magnetic fields:
implications for neuropharmacology and the human population in
the twenty-first century. Cur Neuropharmacol 5: 278-288.
4. Thomas JR, Burch LS, Yeandle SS (1979) Microwave radiation and
chlordiazepoxide: synergistic effects on fixed-interval behavior.
Science 203: 1357-1358.
5. Mevissen M, Kietzmann M, Loescher W (1995) In vivo exposure
of rats to a weak alternating magnetic field increases ornithine
decarboxylase activity in mammary gland by a similar extent as the
carcinogen DMBA. Cancer Lett 90: 207-214.
6. Cook LL, Persinger MA (2000) Suppression of experimental allergic
encephalomyelitis is specific to the frequency and intensity of
nocturnally applied, intermittent magnetic fields in rats. Neurosci
Lett 292: 171-174.
7. Kinoshameg SA, Persinger MA (2004) Suppression of experimental
allergic encephalomyelitis in rats by 50-nT, 7-Hz amplitude-modulated
nocturnal magnetic fields depends on when after inoculation the
fields are applied. Neurosci Lett 370: 166-170.
© Under License of Creative Commons Attribution 3.0 License
2015
Vol. 3 No. 1:2
8. Frenkel K, Wei L, Wei H (1995) 7,12-dimethylbenz[a]anthracene
induces oxidative DNA modification in vivo. Free Radic Biol Med 19:
373-380.
9. Wang L, Yi T, Zhang W, Pardoll DM, Yu H (2010) IL-17 enhances tumor
development in carcinogen-induced skin cancer. Cancer Res 70:
10112-10120.
10.Cherry N (2002) Schumann resonances: a plausible biophysical
mechanism for the human health effects of solar/geomagnetic
activity. Nat Haz 26: 279-331.
11.Cole FE, Graf ER (1974) Precambrian ELF and abiogenesis. In:
Persinger MA (ed)ELF and VLF electromagnetic field effects. Plenum:
NY 243-274.
12.Persinger MA (1996) Enhancement of limbic seizures by nocturnal
application of experimental magnetic fields that simulate the
magnitude and morphology of increases in geomagnetic activity. Int
J Neurosci 86: 271-280.
13.Persinger MA (2003) Rats' preferences for an analgesic compared to
water: an alternative to "killing the rat so it does not suffer". Percept
Mot Skills 96: 674-680.
14.Persinger MA, Lafrenie RM (2014) the cell plasma membrane
potentials as energetic equivalents to astrophysical properties. Int.
Lett. Chem Phys Astron 17: 67-77.
15.Persinger MA (2006) A potential multiple resonance mechanism by
weak magnetic fields affect molecules and medical problems: the
example of melatonin and experimental “multiple sclerosis”. Med
Hypoth 66: 811-815.
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